What Will Lance Armstrong's Legacy Be Now That We Know His Career Was Based on a Lie?

American anti-doping officials plan to strip Lance Armstrong of his seven Tour de France titles and impose a lifelong ban from cycling -- the sport that made him an American hero and a sports icon, it was revealed on Thursday.

The announcement from the US Anti-Doping Agency effectively destroys his legacy as one of the greatest cyclists in history and rubs a black smudge on a story that inspired millions of fans, drawn to his story of returning to glory after recovering from horrific cancer.

The USADA acted within an hour of Armstrong's announcement that he would stop fighting charges that he used blood doping to illegitimately enhance his performance.

Despite the action, Armstrong maintains his innocence and called the USADA's case a 'witch hunt.'

The battle over his Tour de France wins is likely not over. USADA chief executive Travis Tygart said the agency has the authority to remove the titles from the 40-year-old athlete -- and would act promptly to do so.Armstrong says only the International Cycling Union, which oversees the Tour de France, has that power.

'USADA cannot assert control of a professional international sport and attempt to strip my seven Tour de France titles,' he said in a statement. 'I know who won those seven Tours, my teammates know who won those seven Tours, and everyone I competed against knows who won those seven Tours.'

USADA maintains that Armstrong has used banned substances as far back as 1996, including the blood-booster EPO and steroids as well as blood transfusions -- all to boost his performance.

'It is a sad day for all of us who love sport and athletes,' Mr Tygart said. 'It's a heartbreaking example of win at all costs overtaking the fair and safe option. There's no success in cheating to win.'

Armstrong, who retired last year, declined to enter arbitration -- his last option -- because he said he was weary of fighting accusations that have dogged him for years. He has consistently pointed to the hundreds of drug tests that he has passed as proof he was clean.